480 BEPORT— 1891. 



The problem is not quite similar to such cases as that of 

 great rivers like the Amazon, Mississippi, Ehine, the Eiver 

 Plate, in which for hundreds of miles before reaching the sea 

 the river-beds are very fiat, and the currents in the strongest 

 floods have a moderate velocity. Such rivers carry only silt and 

 the finest of sand, which is dispersed by the sea over great 

 areas of its bed, and carried, it may be, hundreds of miles away. 

 The heavy gravels, boulders, and coarse sand brought down by 

 the torrential streams of New Zealand are never carried far 

 out from the beach, and the waves soon heap them on the 

 shore, where they commence their voyage toward the north. 

 One would suppose that the effects of such a stream of materials 

 must leave evidences of some change in the aspect of the 

 shores ; and the apparent absence of any such changes causes 

 many persons to conclude that no such travel is taking place. 

 It is often however forgotten that changes in the grand features 

 of nature which are to be seen at a glance are out of the ques- 

 tion. If in the short lives of men changes were everywhere 

 apparent, nature would assume the instability of human affairs, 

 and that permanence which is her most striking feature would 

 not exist. The changes, however, do exist, but it would take 

 a Methuselah to see them, and for want of any such long-lived 

 men they can only be detected by the reason, and the careful 

 observation of practical observers. 



The materials from the mountains may be disposed of by the 

 sea in several ways : they may be employed in widening the 

 beaches so as to cause the sea-shore to retire seaward ; they 

 may be swept along the shore and gradually ground fine, to 

 ultimately cause shoals and new land to be formed at the end 

 of their journey ; or they may be ground up to the finest sand, 

 and dispersed over the sea-bottom for some miles seaward : and 

 it is most reasonable to suppose that all of these methods of 

 disposal are made use of by the sea. 



Whether the beaches are widening and driving the sea back 

 is difficult to prove, because the process is so very slow, but 

 there seems to be some evidence that at one time at least this 

 operation was at work on our beaches. Besides the enormous 

 accumulations of shingle and boulders that everywhere en- 

 cumber the base of the mountains, in many places, if not every- 

 where, there are found gi'eat deposits of blue clay and soft sand- 

 stone filled with sea-shells and bones of fish. These deposits 

 in many places extend inland almost to the base of the great 

 mountains ; they are covered with enormous deposits of shingle, 

 which is often "found to be composed of rock not now found 

 among the mountains. This would seem to show that the 

 mountains were higher than they are novv', and that their tops 

 were formerly covered with a softer and more shaly rock than 

 the hard crystalline slates and sandstones of the present time. 



